Abstract

We model the nonlinear response of a silica toroid microcavity using coupled-mode theory and a finite-element method, and successfully obtain Kerr bistable operation that does not suffer from the thermo-optic effect by optimizing the fiber-cavity coupling. Our rigorous analysis reveals the possibility of demonstrating a Kerr bistable memory with a memory holding time of 500 ns at an extremely low energy consumption.

W. Yoshiki and T. Tanabe, “Analysis of four-port system for
bistable memory in silica toroid microcavity,” in The 2nd International Symposium on
Photonics and Electronics Convergence (ISPEC2012) (ISPEC, 2012), paper C-4.

W. Yoshiki and T. Tanabe, “Analysis of four-port system for
bistable memory in silica toroid microcavity,” in The 2nd International Symposium on
Photonics and Electronics Convergence (ISPEC2012) (ISPEC, 2012), paper C-4.

Yoshiki, W.

W. Yoshiki and T. Tanabe, “Analysis of four-port system for
bistable memory in silica toroid microcavity,” in The 2nd International Symposium on
Photonics and Electronics Convergence (ISPEC2012) (ISPEC, 2012), paper C-4.

Solid-State Electron. (1)

Other (3)

W. Yoshiki and T. Tanabe, “Analysis of four-port system for
bistable memory in silica toroid microcavity,” in The 2nd International Symposium on
Photonics and Electronics Convergence (ISPEC2012) (ISPEC, 2012), paper C-4.

Figures obtained in an ideal case where the absorption loss in the cavity is determined only by the material. (a) ΔnKerr and ΔnTO versus time when a 6 μW rectangular pulse is input. The wavelength detuning δ between the input light and the initial cavity resonance is 27 fm. τcoup2 is set equal to τint. (b) Pout1 versus Pin of a triangular input pulse with different δ values, where Pout1=|sout1|2. (c) Pout2 versus Pin with different δ, where Pout2=|sout2|2. δ=13, 20, and 27 fm correspond to (3/2)ΔλFWHM, (33/4)ΔλFWHM, and 3ΔλFWHM, respectively. ΔλFWHM is the full-width at half-maximum of the cavity resonant spectrum width. (ΔλFWHM≃15fm). (d) Optical bistable memory operation. The solid, dotted, and dashed curves represent Pin, Pout1, and Pout2, respectively.

ΔnKerr (solid curve) and ΔnTO (dashed curve) versus time for different τcoup2 values in a realistic case. The input pulse power is set at 500×(Qtotτcoup2=τint/100/Qtot)2 in microwatts. The detuning δ is set at 3ΔλFWHM, where ΔλFWHM is 15 fm, 85 fm, and 782 pm when τcoup2 is τint, τint/10, and τint/100, respectively.

Input–output response of a triangular pulse input in a realistic case. (a) Pout1 versus Pin for different τcoup2. (b) Pout2 versus Pin for different τcoup2. The x-axis and y-axis are normalized as Pout1max=Pout2max=Pinmax=1. The detuning δ is set at 3ΔλFWHM. The input pulsewidth is 15 μs, 3 μs, and 0.3 μs and the pulse height is 4.5 μW, 160 μW, and 15 mW when τcoup2 is τint, τint/10, and τint/100, respectively.

Optical memory operation in a realistic case, when δ is 3ΔFWHM. The input power of the drive light is 2 μW, 80 μW, and 7.3 mW, when τcoup2 is τint, τint/10, and τint/100, respectively. The horizontal axis is normalized with the photon lifetime τtot and the vertical axes are normalized as Pout1max=Pout2max=Pinmax=1.

a Estimated from the cavity resonance shift of (1/2)ΔλFWHM. We assume no thermal and carrier diffusion.b The energy change caused by the resonant wavelength shift ΔU=UHWHM((1/2)ΔλFWHM/(λ0+(1/2)ΔλFWHM)) is regarded as Ucons, where UHWHM is the energy that can cause a resonant wavelength shift of (1/2)ΔλFWHM by using the Kerr effect.